<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html lang="en">
<head>
	<meta http-equiv="Content-Type" content="text/html;charset=UTF-8">
	<title>选择器</title>
	<style>
	#one{
		color: yellow;
		font-size: 22px;
	}

	#two{
		color: red;
		font-size: 33px;
	}

	.three{
		color: green;
		font-size: 44px;
	}
	</style>
</head>
<body>
	<h1 id="one">选择器1</h1>
	<h1 id="two">选择器2</h1>
	<h1 class="three">选择器3</h1>
	<h1 class="three">选择器4</h1>
	<h1 class="three">选择器5</h1>
	<h1 class="three">选择器6</h1>
	<h1 class="three">选择器7</h1>
</body>
</html>